| 摘要 |
A travel vibration suppressing device (20) has a directional control valve (30) for a bucket, a directional control valve (29) for a boom, a ride control valve (31), and a boom speed increasing valve (33) that are integrally layered on each other with internal piping. A bottom chamber (11a) of a boom cylinder (11) and an accumulator (27) are communicated or shut off from each other by the ride control valve (31). The boom speed increasing valve (33) is capable of feeding a discharge pressure from a hydraulic pump (21) to the bottom chamber (11a) or a head chamber (11b), and is also capable of connecting the bottom chamber (11a) or the head chamber (11b) to a tank (23). |
